Dual discharge pump



4 INVENTOR .WALTER H. TINKER M p4 f4 1w ATTORNEY 2 SHEETS-SHEET l w. H.TINKER DUAL DISCHARGE PUMP Dec. 30, 1952 Flled Nov 1, 1948 FIG.

Dec. 30, 1952 w. H. TINKER DUAL DISCHARGE} PUMP 2 SHEETSSHEET 2 FiledNov. 1, 1948 INVENTOR WALTER H. TINKE AT TOR N EIY Patented Dec. 30,1952 DUAL DISCHARGE PUMP Walter H. Tinker, St. Louis, Mo., assignor toFairbanks, Morse & Co., Chicago, 111., a. corporation of IllinoisApplication November 1, 1948, Serial No. 57,691

2 Claims. (01. 103-2) This invention relates to improvements incentrifugal pumps, and concerns more particularly an improved pumpassembly of dual discharge character, embodying a single impeller ofnovel construction.

The principal object of the present invention resides'win the provisionof an improved centrifugal pump assembly including separate volutes andembodying a single impeller common to the volutes, the impeller being ofa unitary or one-piece construction, characterized by distinctlyseparate sets of fluid passages one set for each of the volutes, whereinthe passages of one set have their discharge ends radially beyond thedischarge ends of the other set of passages, the pump assembly thusafiording dual, differential pressure fluid delivery.

Another object is to aiford a centrifugal pump assembly providing acasing structure having separate volute chambers, and a single impellerof the character indicated in the foregoing object, affording separatesets of fluid passages each discharging into one of the volute chambers,wherein the assembly includes an effective provision embodied in part inthe impeller structure,

for effecting a fluid seal of the impeller between the volute chamberssuch as to preclude all but a negligible minimum of fluid leakage fromone volute chamber to the other.

Another object resides in the provision of an improved impeller for apump of the character indicated, wherein the impeller provides separatesets of fluid passages, a fluid intake axially of the impeller andcommunicating with the inner ends of the passages of both sets, andmeans in the impeller intake effective to cause a division of the intakefluid into radially separate streams, one stream supplying the passagesof one set and the other stream supplying the passages of the remainingset.

A further object is to provide a pump assembly of the character aboveindicated, which is suitable for use in connection with a jet boosterpump, wherein one fluid discharge of the pump is utilized to energizethe booster pump.

Yet another object is to provide a pump assembly as indicated, in whichthe separate fluid discharges of the pump may be led to independentpoints of use.

Other objects and advantages of the present invention will appearreadily from the following description thereof as illustrated in theaccompanying drawing, wherein:

Fig. 1 is a view in vertical elevation, of a centrifugal pump assemblyincluding a jet booster pump, with portions of the pump assembly andpiping shown in section, showing the presently improved impellerstructure;

Fig. 2 is a fragmentary sectional view of the assembly, illustrating ajet pump and a modified manner of delivering energizing fluid to the jetpump;

Fig. 3 is a fragmentary sectional view of the intake portion of the pumphousing assembly, illustrating a modification in respect to the use ofthe present pump;

Fig. 4 is an enlarged, fragmentary sectional view through thecentrifugal pump, illustrating the novel features of impellerconstruction according to the present invention;

Fig. 5 is a view in plan as taken from line 5-5 in Fig. 1, showing oneof the pump volutes;

Fig. 6 is a similar view but taken along line 6-6 in Fig. 1, showing theother pump volute;

Fig. 7 is a transverse section through the impeller, as viewed from line1-1 in Fig. 4, showing one set of passages thereof, and

Fig. 8 is a transverse section through the impeller as viewed from line8--8 in Fig. 4, showing the other set of passages thereof. Referringfirst to Fig. l, illustrated there is a et boosted centrifugal pumpassembly in which is embodied the present invention. The pump assemblyshown includes a pump casing providmg a lower casing section l0 adaptedas a base section for mounting over the upper end of a well pipe (notshown), and an upper casing section ll supporting on the top thereof, apump drive motor l2. Casing section II is formed to provide an internaltransverse wall I4 having a central opening l5, and an impeller housing[6 of volute character (Fig. 5) on the upper side of the wall l4 andover said opening [5. The housing affords a volute chamber I8 having afluid outlet or discharge neck 19 extending to and opening through theside wall of the casing section, for fluid delivery to a dischargeconduit 20 which for example, may lead to an irrigation system.

Base section It of the casing assembly provides a fluid chamber 22separated from the upper casing section by the wall I4 of the latter,and includes an impeller housing 23 therein, preferably of double ortwin volute character (Fig. 6) affording substantially diametricallyopposite fluid outlets 24. Housing 23 forming the volute chamber 26, isdisposed in cooperative adjacence to the lower side of wall I4 overopening l5 thereof, with the discharge outlets 24 opening directly tothe casing chamber 22. Extending below the central eye 2! of volutehousing 23 is a conduit extension 23 terminating at the bottom wall 30of casing section it in axial fluid-receiving registry with an inletopening 3| in wall 35, the latter opening being threaded to receive thethreaded end of a suction pipe 32. Base section Hi further has a lateralopening 34 shown closed by a plug 35, Fig. l, and an opening 35 inbottom wall 35, threaded to receive a conduit 38. As appears from Figs.1, and 6, the volute 23 is considerably larger in the radial direction,than the volute it, this for a purpose to appear.

Included in the present pumping assembly is a jet booster pump unitenerally designated at, 39,

arranged in the suction line between a suction intake and foot valvedevice 40 and the suction conduit or pipe 32. The jet pump maybe of wellknown construction, providing a jet nozzle 42 having its inlet 53 incommunication with the conduit 38 and its discharge end 44 relativelyspacedfrom but in alignmentwith the intake end 45 of a Venturi tube 41,thelatter connecting with the lower end of suction pipe 32. Well fluidpassing upwardly through the foot valve intake, is received in the jetchamber 48 surrounding the jet nozzle 42, for passageto and through theVen turi tube. V

The depending drive shaft 55 of motor 12 extends through an upwardextension 5| of volute casing l5, and has mounted on its lower end acentrifugal impeller 52 of a novel character in accordance with thepresent invention, the impeller extending through wall opening and beingoperative in both volute chambers l5 and 26. With particular referencenow to Figs. 4, '7 and 8, the impeller 52 is comprised of a unitarymember preferably provided as a single casting of bronze or othersuitable metallic material, formed to have a shaft mounting hub 54 atone end, a portion 55 of a given diameter for operation in the volutehousing IS, a central portion 55 disposed in the opening 15 of wall 14,and an end portion 53 of a diameter exceeding that of the portion 55,operable in the larger volute housing 23. The impeller thus is ofperipherally stepped form to adapt itto the volutes of differing size.Further, the impeller includes an axial, hub-like extension 55externally reduced for a, close running fit in the eye 27 of volutehousing 23 (Fig. 4), the running fitbeing such as to preclude materialleakage or fluidby-pass from the suctionconduit 28 around theimpellersections 59 and 53 to the volute chamber 25. j

Asappears in Fig. 4, the impeller inits central portion 55, is providedwith an outstanding annular rib or flange 50 which is received in anannular shouldered recess 62 formed in the margin of the wall opening[5. Flange 65 has a close running fit in said recess 52, such as toafford a running seal against more than a negli gible amount of fluidleakage between the volute chambers 25 and l8. Such seal materiallyimproves the efficiency of the present pump.

Continuing as to the features of the impeller, the impeller is formed tohave a suction intake provided by an axial bore of stepped character,afiording a large diameter bore 53 and a small diameter bore 64 coaxialwith bore 53 and extending therefrom toward the shaft hub end of theimpeller, the small diameter bore being closed at its inner'end, asshown. Bore 64 extends through the section '56 and'into the section 55of the impeller, while the bore 53 extends through the hub-likeextension 59 and into the section 58, the bore 53 being open at theouter end of extension 55, in fluid-receiving communication with thesuction conduit portion 28 of the volute housing 23. At the junction ofthe bores 63 and 64 is a shoulder provided as an annular, wedgeshapedprojection having its annular apex or tip 5? directed toward the open,fluid inlet end of the large bore 53. The purpose served by the wedgeprojection will appear presently.

Formed in the impeller end section 55 and partly through the centralsection 56, is a set of discharge passages 53 (Figs. 4 and 7) defined byvanes '50 and lateral wall surfaces ll of the impeller member. Eachpassage has its inner end '12 open directly tothe small bore 55, and itsouter end open on the periphery of impeller section 55. Moreover, in thepresently preferred example each passage 58 has a spiral trend divergingoutwardly toward its outer open end 14, as viewed in Fig. 7, and furtherhas an arcuate trend convergently from its inner end 72, as shown in thesectional view of Fig. 4, the latter being in a plane normal to theplane of Fig. 7. In the larger diameter impeller section 58 is-anotherset of discharge passages i5 defined by vanes 75 and lateral wallsurfaces 78 of the impeller. Each passage '15 has its inner end 19 opento the large bore 63 in the region of the annular wedge-like projection55 such that the latter radially underlies the passage opening, whilethe outer end 55 of each passage 15 opens on the periphery of theimpeller section 58. Furthermore, although the passages F5 are generallysimilar to passages 58in respect to a divergent spiral trend as viewedin Fig. 8, and a convergent arcuate trend as appears in'Fig. 4,theydifier not only in length as is obvious, but in the degree of arcuatetrend as appears in Fig. 4. As there shown, the trend in the immediateregion of the outlet opening 55 of each passage 15, is more nearlytransverse to the impeller axis than is the case in respect to theoutlet l iof each passage 68, while the trend in the region of theintake opening 19 is less inclined to the radial than is the case inrespect to the inlet opening 72 of each passage 68. Such differences inthe character of the impeller passages 15 are here presented tofacilitate flow efficiency and high pressure fluid discharge,particularly since in the preferred pump assembly according to Fig, l,--fluid discharged by the impeller passages i5 is utilized to energizethe jet booster pump, as this will appear presently.

In addition to the foregoing, impellereifectiveness and efficiencyare'enhancednot only by curving the impeller vanes '65 and i5 oppositelyto the direction of impeller rotation indicated by-the arrow in each ofFigs. '7 and 8, but also'and importantly here, by giving the intake endportions of these vanes a predetermined angular direction or inclinationto the bore circle of the associated suction intake bore of theimpeller. In each case, the inclination of the inner end or inner tipportion of each vane in the set, is determined in accordance with thediameter-of the associated suction bore, such as to'promotesubstantially shockless entry of fluid to the impeller-dischargepassages formed by the vanes. Thus in the present embodiment and as willbe appreciated by reference to- Figs. 7 and 8, the entrance or pick-upsurface Ella of each vane i5 is given a predetermined inclination to thecircular margin-of suction bore 54, while the pick-up surface l fiaofeach vane 75 has a different predetermined inclination to the circularmargin of suction bore 63. Such inclinations are indicated by the angleA in the first case (Fig. 7), between the entering tip of the vane and atangent to the bore circle passing through the vane tip at the circle,and the similar angle B in the second case (Fig, 8), the angle B beinggreater than the angle A by reason of the greater diameter of suctionbore 63 relative to that of bore 64.

Turning now to the operation of the pumping system shown by Fig. 1, wellfluid passing upwardly in the suction line enters the impeller intakebores 63 and 64. The wedge-shaped projection 66 at the juncture of theimpeller bores 63 and extending at about the angle shown, is eflectiveupon the suction flow to divide the same radially into an outer annularstream directed by the projection into the inlet ends of the impellerpassages 75, and an inner stream directed into the smaller bore 64 forflow to and through the impeller passages 68. The impeller passages 15deliver fluid at high pressure, to the volute chamber 26 from whence thehigh pressure fluid passes out the volute discharge outlets 24 into thecasing chamber 22. From chamber 22 the fluid flows through conduit 38 tothe nozzle 42 of the jet booster pump 39 for energizing the latter in awell known manner, the jet energizing fluid of course, combining withthe well fluid delivered to the impeller intake.

The inner fluid stream entering the impeller bore 64, is dischargedthrough the impeller passages 68 at a pressure materially less than thepressure discharge from the passages I5. Such fluid then passes from thevolute chamber [8 through the discharge neck I 9 to the delivery line23, the latter as shown, having a flow control valve 82 therein.

From the foregoing it will appear now that the present invention affordsa dual discharge pump of centrifugal type, embodying a single, unitaryimpeller providing separate or independent high and low pressure fluiddelivery through separate volutes. While the invention is suitable inparticular, for deep well pumping with suction lift augmented by a jetbooster pump, wherein the operation is as above described in connectionwith the disclosure according to Fig. 1, it will be appreciated that thesingle impeller, dual discharge pump may be employed very effectively,in shallow well pumping in which a jet pump is unnecessary. Conversionto shallow well use may be effected readily, merely by removing the jetpump unit, extending the suction conduit 32 directly to the foot valveand suction intake device 40, and closing the casing opening 36 by asuitable plug 83 as illustrated in Fig. 3. Eflective pumping then willobtain only through the impeller passages 68 to discharge deliverythrough line 20, the impeller portion containing passages 15 thenrunning idle. However, in shallow well pumping full use of the dualdischarge function of the pump may be had by removing the plug 35closing opening 34 (Fig. l), and leading a conduit (not shown) from saidopening to a point of fluid use, as for example, to a pressure tanksupplying water for domestic or other use. The high pressure dischargeeffected by the impeller passages 15 is especially suitable for thelatter purpose, as will be appreciated, while the low pressure deliverythrough line 23 may be used for irrigation or other use requiring lowpressure, large volume flow of fluid. It is to be noted here that fluiddelivery may be eflected both through line 20 and a line from the casingopening 34, in the dee well, jet pump arrangement of Fig. 1, but in suchcase, it will be '6 appreciated that there will be a decrease in theeffectiveness of the jet pump because of the divi sion of high pressurefluid discharge between the jet pump and the line from casing opening34.

In the instance of a deep well system wherein the diameter of the wellcasing is not suflicient to accommodate a suction line and jet boosterarranged as shown in Fig. 1, the compact arrangement as illustrated byFig. 2, may be employed. As there shown, the well casing 9|] is employedas a delivery conduit for the jet operating, high pressure fluid fromthe pump casing chamber 22. A fitting 9| is secured to the upper end ofwell casing 90, the fitting providing an elbow conduit 92 which isconnected to chamber opening 36 by a short length of pipe 94. Highpressure fluid thus is delivered downwardly in well casing 39 about thesuction pipe 95 and Venturi tube 96, to the inlet of the jet nozzle 98of jet pump unit 39. To prevent by-pass of the jet energizing fluid tothe well suction intake I00, the well casing below the jet unit, isclosed by suitable seal rings I32.

Having now fully described and illustrated the present invention, whatis desired to be claimed and secured by Letters Patent is:

1. An impeller for a centrifugal pump, com prising a unitary member witha stepped periphery and having separate sets of discharge passagestherein, with one set of passages opening on one peripheral step andanother set of passages opening on another peripheral step of themember, the member further having a fluid inlet bore in directcommunication with one set of the passages, and a portion of the memberbetween said sets of passages providing a wedgeshaped projectionterminating in an annular tip within the fluid inlet bore and in theproximity of the set of passages directly communicating with said inletbore, the said portion of the member thereby defining a coaxial reduceddiameter extension of said inlet bore leading to the other set ofpassages, the wedge-shaped projection being effective for dividing thefluid entering said inlet bore into radially separate streams individualto the sets of discharge pasages in the impeller.

2. A centrifugal pump assembly including a casing having an internaltransverse wall with a central opening and means forming volute chamberson opposite sides of the wall over said opening, the marginal walldefining said opening in the wall member providing a shouldered recess,and an impeller comprising a unitary member with a continuous steppedperiphery operable in said volute chambers and extending through saidopening in the wall so that the stepped impeller periphery and theshouldered recess engage to effect a running seal of the impeller in theopening, the impeller being provided with separate sets of dischargepassages therein, with one set of passages opening on one peripheralstep of the member to one of the volute chambers on one side of therunning seal and another set of passages opening on another peripheralstep of the member to the other of the volute chambers on the other sideof the running seal, the impeller being further provided with a fluidinlet bore in direct communication with one set of the passages and witha portion of the member between said sets of passages providing awedge-shaped projection terminating in an annular tip within the fluidinlet bore and in the proximity of the set of passages directlycommunicating with said inlet bore, the said portion 7 of the memberthereby defining a, coaxial I6?- duced diameter extension of the inletbore. leading to. the other set of passages, the Wedgeshaped projectionbeing effective for dividing the fluid entering said inlet bore intoradially separate. streams, individual to the sets of dischargepassages.

WALTER H. 'I'INKER.

REFERENCES CITED The foil'owing references are of record in the file ofthis patent:

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